Using infrared light for photos

No longer need Photoshop thanks to an invisible light

Infra-red light has the property of penetrating the skin. When used in portrait photography, it improves the color and eliminates any imperfections. It’s easier than Photoshop! Combining color images and infra-red light gives spectacular results. You can now experience this for yourself at the Swiss Camera Museum in Vevey, using the rather special photo-booth installed by the Audio Visual Communications Laboratory.

The laboratory staff are working on algorithms that imitate the processing of images by the eye and brain, and are exploring new avenues offered by the properties of infra-red. This invisible light enhances the quality of digital photos, and brings out details that enable the perfection of mathematical models.

On the left, the skin shows some minor imperfections. Thank to the infrared process, the portrait on the right shows an almost perfect skin. Such a technology may be implemented in digital cameras.

How to judge whether a photo is good?

Difficult question! All living species have varying perceptions of color. Man sees a spectrum from red to violet. However, his interpretation of images and colors is never purely physical, because in the process the information is conditioned by the brain.

To transfer this subjective aspect of human vision to a computer is one of the research areas of Sabine Süsstrunk’s laboratory. Twenty years ago, the film used in conventional cameras began to be replaced by digital technology, and during those 20 years digital photography has tried to imitate film, although the former has a lot more to offer. The silicon sensors in our digital cameras are sensitive not only to visible light, but also to infra-red.

Today, we are exploring new developments, particularly in the area of computational photography.

Penetrating the haze

Infra-red light instantly re-touches the texture of the skin, but it also enables us to get over obstacles that the eye and lens cannot normally overcome. Thus, the “artistic” haze that blurrs the mountains in a panorama is penetrated by infra-red. The details burst out of the picture. By merging a color photo with infra-red, the image is rendered much more “readable”, and also more precise.

Recognizing and focusing

“By using infra-red, we want to improve the algorithms so that our machines become as rapid and precise as the human eye.” Neda Salamati, PhD assistant, uses color and infra-red signals to make computer vision more “intelligent”, enabling it to recognize an object, regardless of its kind or its setting.

This is important, because what attracts a human eye leaves a computer cold. This is another trail being explored by the Audio Visual Communications Laboratory: to give computers the ability to recognize salient objects, which naturally attract the human eye.

- For more information: see the complete file on the Audio Visual Communications Laboratory in the latest edition of Flash.

- The Audio Visual Communications Laboratory is taking part, with Archizoom and the Musée de l’Elysée, in the "Nuit des musées". Everybody's invited to take photographs of public spaces and to download them to They will be projected on to a giant screen at the Rolex Learning Center.

Author: Sandy Evangelista

Source: EPFL